Studies on the Characteristics of Aluminum Based Solid State Capacitor with Poly(3,4-ethylenedioxythiophene) as Electrolyte

• Main Authors: Hung-Ming Wang, 王鴻明
• Other Authors: Chin-Tsou Kuo
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/70208290053633638196

碩士 === 大同大學 === 化學工程學系(所) === 96 === ABSTRACT Conductive polymer film made of poly(3,4-ethylenedioxythiophene) (PEDOT) is applicable to conventional aluminum solid electrolytic capacitors, and fit to substitute for conventional electrolyte or function as solid state electrolyte, enabling components made thereof to be small sized, high capacitance, highly reliable, long life, thermal stability, and high frequency, and becoming in wider use. This study is aimed at exploration of related characteristics of PEDOT applied to formed onto the aluminum foil and configured to function as electrolyte for fabricating solid state electrode. A high frequency and a low impedance capacitor could be obtained by utilizing polymerization on prepared conductive polymer film to aluminum oxide film and performing impregnation once at low temperature. Laboratory results show that the most suitable operation conditions for monomer is under impregnation and the proportion of monomer to methanol should be 1:4. No matter it's vacuumed at 300 mmHg at 55℃ or without vacuumed at 65℃, it makes no influence for solvent being evaporated. Putting 0.3 g of oxidant CB-55 under impregnation at the low temperature of 5 ℃for 30 min and setting high temperature polymerization at 120 ℃ for 30 min, the best characteristics of capacitance with capacitance (Cs) of 653 μF, dissipation factor (DF) of 2.16%, equivalent series connected resistance (ESR) of 8.86 mΩ at 100 kHz, and leakage current of 62 μA, could be gained provided that elements were not pre-cooled. In conclusion, this study reveals that the solid state electrolyte fabricated with conductive polymer has equivalent features to those of the NIPPON CHEMI-CON PS Series. Moreover, in terms of manifests thermal stability, it's passed a service life evaluation test conducted at 105 °C for 2000 hours under atmospheric pressure. The result of this research indicates that conductive polymer based on solid state electrolyte fabricated has much better performance including lower impedance than those of liquid state electrolyte capacitor. In addition, passing through a high temperature service life test, the manifests stable electrical characteristics has certainly brought a significant commercial value in the market.